I understand that this is a topic that challenges most folks in the sous vide world. I’ve tried doing many of the tips that I’ve seen around with vary amounts of success. Sealing flatware in the bag, or clipping flatware to the bag had OK results for many items. When I cook vegetable at higher temps, though the steam just floats about everything.
Until today the best trick that has worked for me is putting a small plate on the bag and then weighing it down with a quart jar filled with water. Guess what, this worked well with a single veggie, but try to cook two servings, and it still floats. Answer? Add another jar. I’m running out of room! The advantage of sous vide is being lost to the crowded pot! Low circulation means poorly cooked food! I needed a better solution.
Today I decided to try something different. I am a professional chimney sweep. As such I have access to 316 Stainless steel expanded metal mesh. This mesh is commonly used for chimney caps. It has a diamond shape with free areas that are 3/4 by 1 3/4 inches. It is pretty heavy stuff. I found, however, it cuts easily with diagonal cutters such as electricians use.
I was able to cut a circle that fits snugly in my sous vide pot. It has enough friction to hold sown FOUR servings of veggies! Now I can keep the food submerged AND float ping pong balls on top!
You can find a chimney sweep, such as myself, at the Chimney Safety Institute of America, http://www.csia.org . Enter your zip code to find one local to you! All the major suppliers sell this mesh in various quantities so your sweep should be able to get some for you.
While you are at it, schedule a chimney inspection and cleaning !
Happy sous vide with your food submerged!